[Qemu-devel] [RFC PATCH for-4.1 0/7] CET support

[Paolo Bonzini]

These patches add support for control flow protection, and as a bonus
while no one actually has machines that support CET, a faster x86-specific
coroutine backend.

I have tested the first six; I cannot yet test the seventh because
my CET machine has an old kernel without ARCH_X86_CET_ALLOC_SHSTK
support.

Unfortunately, I'm seeing a 60x performance drop with IBT (!).  It
may be (or so I hope) a problem with this particular machine, but
anyway for now CET is left disabled...

Paolo

Paolo Bonzini (7):
  qemugdb: allow adding support for other coroutine backends
  coroutine: add x86 specific coroutine backend
  configure: add CET support
  tcg: add tcg_out_start
  tcg/i386: add support for IBT
  linux-user: add IBT support to x86 safe-syscall.S
  coroutine-x86: add CET shadow stack support

 Makefile.target                           |   5 +
 configure                                 |  60 +++++
 linux-user/host/i386/safe-syscall.inc.S   |  19 ++
 linux-user/host/x86_64/safe-syscall.inc.S |  19 ++
 scripts/qemugdb/coroutine.py              | 107 +++-----
 scripts/qemugdb/coroutine_ucontext.py     |  69 +++++
 scripts/qemugdb/coroutine_x86.py          |  21 ++
 tcg/aarch64/tcg-target.inc.c              |   4 +
 tcg/arm/tcg-target.inc.c                  |   4 +
 tcg/i386/tcg-target.inc.c                 |  18 ++
 tcg/mips/tcg-target.inc.c                 |   4 +
 tcg/ppc/tcg-target.inc.c                  |   4 +
 tcg/riscv/tcg-target.inc.c                |   4 +
 tcg/s390/tcg-target.inc.c                 |   4 +
 tcg/sparc/tcg-target.inc.c                |   4 +
 tcg/tcg.c                                 |   2 +
 tcg/tci/tcg-target.inc.c                  |   4 +
 util/Makefile.objs                        |   5 +
 util/coroutine-x86.c                      | 298 ++++++++++++++++++++++
 19 files changed, 580 insertions(+), 75 deletions(-)
 create mode 100644 scripts/qemugdb/coroutine_ucontext.py
 create mode 100644 scripts/qemugdb/coroutine_x86.py
 create mode 100644 util/coroutine-x86.c

-- 
2.20.1